Dehumidification

[dantownehall]

My un-air conditioned unheated basement is kinda damp and gross, and smells pretty musty & fuggy.  A friend with a moisture meter confirmed I have a situation.

I want to do something about it that hopefully doesn't involve running an expensive electric appliance 100% of the time.

Any thoughts?

[MDM]

To reduce the amount of water in your basement air, there are at least two approaches:
1) Stop water from entering your basement, both from liquid leaks and ambient humidity.
    - Start here (i.e., seal all cracks) because prevention is better than cure.
2) Remove water from the air (aka dehumidification as your thread title suggests).

See
http://forum.mrmoneymustache.com/do-it-yourself-forum!/stopping-musty-basement-smell
http://forum.mrmoneymustache.com/ask-a-mustachian/feedback-on-whether-a-dehumididfier-is-a-good-idea
http://forum.mrmoneymustache.com/ask-a-mustachian/why-does-my-electricity-usage-still-suck/msg72009/#msg72009
http://forum.mrmoneymustache.com/do-it-yourself-forum!/correcting-basement-leaks-from-subsurface-water
for previous posts on the subject.

If you keep your above-grade airspace at low humidity, there are systems that blow basement air outside, thus pulling the low humidity air down to the basement.  Pros and cons to that approach as well.

[MrFrugalChicago]

Also note that doing nothing will be a HUGE Problem down the road, as at 60-65% humidity levels you can start to grow black mold, which is thousands of dollars to remove (and potentially causes health problems).

I bought a ~$150 humidifier, that cost ~$10 in electricity a month to keep my basement at 45% or lower humidity. But I get 1200 square feet of basement to use, so a pretty good investment (and much cheaper per square foot than upstairs as the heating and cooling costs are much lower).